TwinCAT 3 ADS Error 7: Target Machine Not Found, what to check?
I'm trying to connect my engineering PC to a new TwinCAT 3 runtime, but I keep getting ADS Error 7 (0x7) "Target Machine Not Found". The runtime is definitely up and running. What should I check first?
ADS Error 7 (0x7) indicates that the local ADS router on your client machine (engineering PC or HMI) cannot find a route to the target's AMS NetId. This means the connection request never leaves your client. This often happens on initial connections or after changes to the target's network configuration.
Likely causes and checks
1No ADS route configured for the target
- Points to it
- The client (engineering PC or HMI) does not have a static route defined for the target's AMS NetId, preventing any communication attempts.
- Check
- Verify the static routes on your client machine. Also, ensure a reverse route is configured on the target system, as both sides need to know each other for communication.
2AMS NetId in the client does not match the target
- Points to it
- The AMS NetId configured in your client for the target does not match the actual AMS NetId of the target system. This can happen if the target was replaced or its NetId was manually changed.
- Check
- Compare the AMS NetId configured in your client with the target's actual AMS NetId. You can find the target's NetId in 'SYSTEM > Routes > NetId Management' or via the TwinCAT SysTray Router. Remember that the target must be restarted after an AMS NetId change.
3Route points to an old IP address or hostname
- Points to it
- The existing ADS route for the target contains an outdated IP address or hostname, meaning the client is trying to connect to the wrong network location.
- Check
- Check the IP address or hostname stored in the ADS route on your client and confirm that the target system is currently reachable at that address.
Next check: If the route exists and the error persists, ensure that incoming TCP port 48898 (for communication) and UDP port 48899 (for broadcast search) are allowed through any firewalls on the target system, as these are required for ADS communication.
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